Robotically controlled medical systems such as employed for minimally invasive medical procedures can include complex equipment to precisely control and drive medical instruments. (As used herein, the terms “robot” or “robotically” and the like include teleoperation or telerobotic aspects.) FIG. 1A illustrates an example of a known robotically controlled system 100. System 100, which may, for example, be part of a da Vinci® Surgical System available from Intuitive Surgical, Inc., includes a patient-side manipulator 110 having multiple arms 130. Each arm 130 has a docking port 140 that generally includes a drive system with a mechanical interface for mounting and providing mechanical power for operation of an instrument 150. Arms 130 can be used during a medical procedure to move and position respective medical instruments 150 for the procedure.
FIG. 1B shows a bottom view of a known medical instrument 150. Instrument 150 generally includes a transmission or backend mechanism 152, a main shaft 154 extending from the backend mechanism 152, and a functional tip 156 at the distal end of main shaft 154. Tip 156 generally includes a medical tool such as a scalpel, scissors, forceps, or a cauterizing instrument that can be used during a medical procedure. Drive members 155 such as cables or push-pull rods connect to tip 156 and extend through main shaft 154 to backend mechanism 152. Backend mechanism 152 typically provides a mechanical coupling between drive members 155 of instrument 150 and motorized axes of the mechanical interface of docking port 140. In particular, backend mechanism 152 typically contains mechanical elements such as capstans, gears, and levers that convert rotational movement of drive motors into linear motion of tendons or push rods 155.
Instruments 150 of system 100 can be interchanged by removing one instrument 150 from a docking port 140 and then installing another instrument 150 in place of the instrument removed. Equipment such as patient-side manipulator 110 is often covered for a medical procedure by a sterile barrier because of the difficulty in cleaning and sterilizing complex equipment between medical procedures. These sterile barriers can include a plastic sheet and a sterile adaptor (not shown) that is interposed between docking port 140 and instrument backend 152. However, instruments 150 are on the patient side of the sterile barrier and are generally subject to surgical sterile protocols. The complexity of backend mechanism 152 can make sterilization of instruments 150 difficult particularly if an instrument is intended to be reused for multiple medical procedures. The complexity of backend mechanism 152 also increases the cost of instrument 150, which is particularly a concern when an instrument is intended to be a single use device.